Fun or the fun

Hi,
Since Christmas is almost arriving, my friends invite me to a get-together. But unfortunately, I have to do some errands around the same time, I wonder which one is correct to say:

"Hi, I might be late. I don't want to miss all the fun."
Or can I say," I don't want to miss the fun." Or, "I don't want to miss fun."
Since I didn't mention which fun is explicitly. Is okay to say"the"? and is it okay to add"all" as well in the sentence?

Thanks,